Answer:
Mean track length for this rock specimen is between 10.463 and 13.537
Step-by-step explanation:
99% confidence interval for the mean track length for rock specimen can be calculated using the formula:
M±
where
- M is the average track length (12 μm) in the report
- t is the two tailed t-score in 99% confidence interval (2.977)
- s is the standard deviation of track lengths in the report (2 μm)
- N is the total number of tracks (15)
putting these numbers in the formula, we get confidence interval in 99% confidence as:
12±
=12±1.537
Therefore, mean track length for this rock specimen is between 10.463 and 13.537
(3x2 + 9x + 6) − (8x2 + 3x − 10) + (2x + 4)(3x − 7)
First distribute the (2x+4)(3x-7) to get 6x2-2x-28
After this just add the like terms for all parts of the expression.
(3x2-8x2+6x2)+(9x-3x-2x)+(6+10-28)
x2+4x-12
So you answer is x2+4x-12
Since distance equals speed times time (d = st), we have
t = d/s
where d = 120 miles and s = 15 miles per hour
t = d / s
t = 120 / 15
t = 8
It will take 8 hours to drive 120 miles at a speed of 15 miles per hour.
Answer:
(a d)/(bc)
Step-by-step explanation:
a/b ÷ c/d
Copy dot flip
a/b * d/c
ad / bc
Answer:
C
Step-by-step explanation:
When we write an equation, we look for something like is or equals
A.twice as much as a number 2x
B.12 less than a number x-12
C.half of a number is 15 1/2x =15
D.the difference of 20 and a number? 20-x
A,B, and D are expressions
